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MgGa2O4 (MGO) with the spinel structure exhibits abundance defects and could achieve the modulation of emission by ion doping as persistent luminescence nanoparticles (PLNPs). Here, we introduced Cr3+ ions into MGO to achieve near-infrared (NIR) emission, and Pr3+ ions to tune the lattice environment for enhanced NIR emission. The optimal composite, MgGa2O4: 0.005Cr3+, 0.003Pr3+ (MGCP), achieved enhanced NIR emission at 709 nm under 222 nm excitation. The concentration quenching was observed due to electric dipole-quadrupole interaction at high Cr3+ and Pr3+ content. The afterglow mechanism was revealed, while the energy-splitting occurs from trivalent Cr3+ ions at 650 and 709 nm, thanks to the complex lattice environment. We observed that the emission at 709 nm decreased, while the satellite signal at 650 nm increased first and then decreased intensity with increasing temperature, due to the intervalence charge transfer for Cr3+ ions at 303-528 K. Ratiometric temperature sensing was therefore realized with superb linearity, high absolute sensitivity at 303 K for 4.18%, and accuracy at 528 K for 2.62 K, confirming with the luminescence intensity ratio at 709 and 650 nm under excitation at 222 nm. Thus, we provide a method with energy-splitting emission of Cr3+ ions to design temperature sensing.
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BACKGROUND: To investigate the difference between the predicted preoperative corneal ablation depth and the measured ablation depth for femtosecond laser in situ keratomileusis (FS-LASIK) in patients with different degrees of myopia, and to analyze the source of the difference. METHODS: A total of 55 patients (109 eyes) were included in this study. Multiple logistics regression was applied to analyze the sources affecting postoperative refractive outcomes. The difference between the preoperative predicted corneal ablation depth and the 1-day postoperative ablation depth in patients with different degrees of myopia was explored using linear regression. Corneal biomechanical parameters influencing error in ablation depth calculation were examined using multiple linear regression. RESULTS: One hundred and nine eyes were divided into low to moderate myopia (55 eyes, myopia of 6 D or less), high myopia (45 eyes, myopia ranging from 6 D to a maximum of 9 D), and very high myopia group (9 eyes, myopia greater than 9 D) based on preoperative refractive error (spherical equivalent). Postoperative visual outcomes were comparable among the three groups of patients, with no significant difference in uncorrected visual acuity (UCVA). We did find notable disparities in spherical equivalent (SE) and central corneal thickness (CCT) in patients with different degrees of myopia at 1 day postoperatively (all p < 0.001). Logistic regression analysis showed that error in ablation depth calculation was an independent risk factor for refractive outcomes one day after surgery (OR = 1.689, 95% CI: 1.366 - 2.089). There was a substantial discrepancy in error in ablation depth calculation at 1 day postoperatively between the three groups. The measured ablation depth of the laser platform was lower than the predicted ablation depth in the low to moderate myopia and very high myopia groups, but the opposite was true in the high myopia group. Pre-operative SE (p < 0.001) and corneal front minimum radius of curvature (Front Rmin) (p = 0.007) obviously influenced the error in ablation depth calculation. CONCLUSIONS: Error in ablation depth calculation values vary significantly between patients with different degrees of myopia and correlate highly with preoperative SE and Front Rmin. At the same time, the available evidence suggests that error in ablation depth calculation is an influential factor in postoperative refractive status, so it is imperative to control error in ablation depth calculation.
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Ceratomileuse Assistida por Excimer Laser In Situ , Miopia , Humanos , Estudos Prospectivos , Lasers de Excimer/uso terapêutico , Córnea/cirurgia , Refração Ocular , Miopia/cirurgiaRESUMO
OBJECTIVE: Diabetic nephropathy is one of the most important microvascular complications of diabetes, which mainly refers to glomerular capillary sclerosis. Podocytes are an important part of glomerular capillaries. Previous clinical and basic studies have shown that fibrosis is the main factor of diabetic nephropathy. This study aimed to assess the protective mechanism of glycyrrhizic acid (GA) on glomerular podocytes induced by high glucose as we hypothesized that GA may have antifibrotic and anti-inflammatory effects on podocytes through regulation of the adenosine 5'-monophosphate-activated protein kinase (AMPK)/sucrose nonfermenting AMPK-related kinase (SNARK) signaling pathway. METHODS: SNARK siRNA was used to transfect podocytes. Real-time quantitative polymerase chain reaction and immunofluorescence staining assays were used for molecular and pathological analysis. The expression levels of key pathway proteins (including TGF-ß1, α-SMA, SITR1, AMPKα, LKB1, PGC-1α, NF-κB, IL-6, and TNF-α) were verified by Western blotting. The expression of inflammatory factors in podocytes was detected by ELISA. RESULTS: We demonstrated that GA decreased the expression of podocyte fibrosis signaling pathway-related factors by upregulating the AMPK pathway and its related factors. However, after transfection of podocytes with SNARK siRNA, there was an increased expression of fibrosis-related factors and inflammation-related factors. CONCLUSION: GA can protect podocytes and alleviate fibrosis and inflammation induced by high glucose, which is related to the AMPK signaling pathway. Meanwhile, knockdown of SNARK protein can inhibit the AMPK signaling pathway, aggravate fibrosis, and increase inflammation.
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Nefropatias Diabéticas , Ácido Glicirrízico , Podócitos , Humanos , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/metabolismo , Fibrose , Glucose/metabolismo , Ácido Glicirrízico/farmacologia , Ácido Glicirrízico/metabolismo , Inflamação/patologia , RNA Interferente Pequeno/metabolismo , Transdução de SinaisRESUMO
BACKGROUND: The development of venous thromboembolism (VTE) is associated with high mortality among gastric cancer (GC) patients. Neutrophil extracellular traps (NETs) have been reported to correlate with the prothrombotic state in some diseases, but are rarely reported in GC patients. AIM: To investigate the effect of NETs on the development of cancer-associated thrombosis in GC patients. METHODS: The levels of NETs in blood and tissue samples of patients were analyzed by ELISA, flow cytometry, and immunofluorescence staining. NET generation and hypercoagulation of platelets and endothelial cells (ECs) in vitro were observed by immunofluorescence staining. NET procoagulant activity (PCA) was determined by fibrin formation and thrombin-antithrombin complex (TAT) assays. Thrombosis in vivo was measured in a murine model induced by flow stenosis in the inferior vena cava (IVC). RESULTS: NETs were likely to form in blood and tissue samples of GC patients compared with healthy individuals. In vitro studies showed that GC cells and their conditioned medium, but not gastric mucosal epithelial cells, stimulated NET release from neutrophils. In addition, NETs induced a hypercoagulable state of platelets by upregulating the expression of phosphatidylserine and P-selectin on the cells. Furthermore, NETs stimulated the adhesion of normal platelets on glass surfaces. Similarly, NETs triggered the conversion of ECs to hypercoagulable phenotypes by downregulating the expression of their intercellular tight junctions but upregulating that of tissue factor. Treatment of normal platelets or ECs with NETs augmented the level of plasma fibrin formation and the TAT complex. In the models of IVC stenosis, tumor-bearing mice showed a stronger ability to form thrombi, and NETs abundantly accumulated in the thrombi of tumor-bearing mice compared with control mice. Notably, the combination of deoxyribonuclease I, activated protein C, and sivelestat markedly abolished the PCA of NETs. CONCLUSION: GC-induced NETs strongly increased the risk of VTE development both in vitro and in vivo. NETs are potential therapeutic targets in the prevention and treatment of VTE in GC patients.
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Armadilhas Extracelulares , Neoplasias Gástricas , Trombofilia , Trombose , Tromboembolia Venosa , Animais , Constrição Patológica , Células Endoteliais/metabolismo , Armadilhas Extracelulares/metabolismo , Fibrina , Camundongos , Neutrófilos/metabolismo , Neoplasias Gástricas/complicações , Neoplasias Gástricas/metabolismo , Trombose/etiologia , Tromboembolia Venosa/etiologia , Tromboembolia Venosa/metabolismoRESUMO
Grazing, one of the main grassland utilization modes, has notable impacts on grassland ecosystem structure and functions. However, the effects of long-term grazing on soil aggregate composition and stability are poorly understood. Based on a long-term grazing experiment platform in Inner Mongolia Stipa breviflora desert steppe established in 2004, with treatements of no grazing (control), light, moderate, and heavy grazing intensities, we studied the changes of soil aggregate composition and stability under different grazing intensities. With the measurement of relevant soil physical and chemical characteristics, we explored the main factors that affecting the stability of soil aggregates. The results showed that grazing significantly altered soil aggregate composition. Compared with control, the content of large aggregates (0.25-2 mm) was unchanged in light grazing but significantly decreased in treatments with moderate and heavy grazing intensities. Heavy grazing significantly decreased the content of small aggregates (0.053-0.25 mm), while light and moderate grazing significantly increased that of microaggregates (<0.053 mm). Soil aggregate stability was maintained at a high level under light grazing, but significantly decreased under moderate and heavy grazing treatments. Soil aggregate stability was positively correlated with macroaggregate content but negatively correlated with microaggregate content. Soil pH, bulk density, organic carbon and other physicochemical indices jointly contributed to the changes of soil aggregate composition and hence affect soil aggregate stability. In conclusion, our results showed that appropriate grazing could maintain high level of soil aggregate stability in desert steppe.
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Ecossistema , Solo , Solo/química , China , Poaceae , Carbono/análise , PradariaRESUMO
We conducted an experiment to test the characteristics and differences of the spatial distribution of constructive species Stipa breviflora at different scales under different stocking rates in the S. breviflora desert steppe in Siziwang Banner, Inner Mongolia. The spatial distribution of S. breviflora under four treatments (control, light grazing, moderate grazing, and heavy grazing) at different scales (small scale as 1 m×1 m and mesoscale as 5 m×10 m) were analyzed. The results showed that the population density of S. breviflora at mesoscale in the control and light grazing was significantly lower than that at the small scale. Grazing significantly increased the population density of S. breviflora in the meso- and small scales. At the small scale, the population distribution of S. breviflora in the control, light grazing, moderate grazing, and heavy grazing treatments conformed to linear, exponential, exponential and exponential models, respectively, and Gaussian, exponential, Gaussian and exponential models at mesoscale fitted by semi-variance function. The spatial distribution pattern at small scales in the control was simple and better but was more complex and poorer under the heavy grazing. At the mesoscale, it was simple and better under the heavy grazing but complex and poor under the moderate grazing. The spatial heterogeneity of S. breviflora population reduced and were more uniform under the moderate and heavy grazing at meso- and small scales. In addition, the trend of population distribution in the enclosure, moderate and heavy grazing were generally the same, while light grazing showed inconsistent trend at different scales.
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Poaceae , ChinaRESUMO
This study evaluated the changes of spatial distribution of the constructive species Stipa breviflora in the desert steppe under different grazing intensities (control, light, moderate, and heavy grazing) in Siziwang, Inner Mongolia. The small-scale spatial distribution of S. breviflora was measured. Results showed that population density of S. breviflora was following the order: heavy grazing (27.81 individuals·m-2) > moderate grazing (22.17 individuals·m-2) > control (11.31 individuals·m-2) > light grazing (10.76 individuals·m-2). The moderate and heavy grazing significantly increased population density of S. breviflora. According to the model fitting by semi-variance function, the population density of S. breviflora under the control, light, moderate and heavy gra-zing treatments were consistent with the exponential model, spherical model, exponential model and spherical model, respectively. Results from spatial distribution pattern analysis showed that structural ratio of S. breviflora population was control (99.7%) > heavy grazing (94.7%) > light grazing (92.7%) > moderate grazing (87.9%). Such a result indicated that the spatial autocorrelation of the four treatments was high, which were mainly affected by structural factors. In comparison, S. breviflora population structure ratio under moderate grazing treatment was the smallest, and partly affected by random factors. Based on fractal dimension analysis, spatial structure of the four treatments was good with simple spatial distribution. With the increases of grazing intensity, the spatial distribution was simpler and more homogeneous. Combined with 2D and 3D views, both light and heavy grazing changed spatial distribution of S. breviflora population from gradient distribution to patch distribution and resulted in the reduction of spatial heterogeneity.
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Ecossistema , Meio Ambiente , Herbivoria , Poaceae/fisiologia , China , Análise EspacialRESUMO
An efficient synthesis of 1,4-disubstituted 1,2,3-triazole derivatives was studied. 1,4-Disubstituted 1,2,3-triazoles containing isoxazole and thymidine structures were synthesized in 84-96% yields starting from various terminal isoxazole ether alkynes and ß-thymidine azide derivatives via a 1,3-dispolar cycloaddition using copper acetate, sodium ascorbate as the catalyst under ultrasonic assisted condition. All the target compounds were characterized by HRMS, FT-IR, 1H NMR and 13C NMR spectroscopy. Furthermore, the quorum sensing inhibitory activities of synthesized compounds were evaluated with Chromobacterium violaceum (C. Violaceum CV026) based on their inhibition of violacein production, with compound C10-HSL as a positive control. The compounds 8a, 8c and 8f exhibited considerable levels of inhibitory activity against violacein production, and IC50 values were 217±19, 223±20 and 42.8±4.5µM, respectively, which highlighted the potential of these compounds as lead structures for further research towards the development of novel QS inhibitors.
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Alcinos/química , Azidas/química , Percepção de Quorum/efeitos dos fármacos , Triazóis/síntese química , Triazóis/farmacologia , Ondas Ultrassônicas , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Técnicas de Química Sintética , Chromobacterium/citologia , Chromobacterium/efeitos dos fármacos , Triazóis/químicaRESUMO
A metal-dependent and complementary catalytic method to synthesize the cyclohexadienes has been developed. When gold or indium salts were used as catalysts, 1,3-cyclohexadiene (1,3-CHD) could be obtained; when Cu(OTf)2 was used as the catalyst, however, another isomer 2,4-cyclohexadiene (2,4-CHD) was furnished instead.
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Cicloexenos/química , Cicloexenos/síntese química , Metais/química , Alcenos/química , Alcinos/química , Catálise , Técnicas de Química Sintética , Isomerismo , Especificidade por SubstratoRESUMO
Raman spectroscopy can be used in situ real-time measurement because it's rapid, and it is helpful to real-time online monitoring of process control. With the complexity of the environment and the characteristics of Raman signal, it is hard to avoid some overlapping spectrum peaks. Based on the advantage of immune algorithm, an immune algorithm (IA) was applied to the overlapping Raman signals of aromatics. With extraction of each single Raman spectrum peak signal from the mixture signals for resolution, Results show that the method is effective to identify the overlapped Raman signal for its fast resolution and accurate quantitative determination with the relative error less than 1%. For the overlapping Raman signals with fluorescence background disturbance, we proposed an adaptive immune algorithm, which is combined with independent component analysis. It can effectively resolve the fluorescence background signal, and it provides a new way for Raman spectra analysis of complex samples.
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Syntheses, structures, and properties of univalent coinage metal 2-methylimidazolate supramolecular isomers [M(mim)] (1, M = Cu; 2, M = Ag) were investigated in detail. In addition to the known isomers, namely, zigzag chains [Cu(mim)] (1a) and [Ag(mim)] (2a), molecular octagon [Cu(8)(mim)(8)]·C(6)H(6) (1b), decagon [Cu(10)(mim)(10)]·C(8)H(10) (1c), helical chain [Ag(4)(mim)(4)]·C(6)H(6) (2b), and S-shaped chain [Ag(4)(mim)(4)]·C(8)H(10) (2c), two new structures including a polyrotaxane [Cu(10)(mim)(10)]·[Cu(mim)] (1d, C2/m, a = 14.452(4) Å, b = 27.712(7) Å, c = 11.427(3) Å, ß = 125.899(4)°, V = 3707(2) Å(3)) and a new octagon [Ag(8)(mim)(8)]·Me(2)CO (2d, C2/c, a = 21.852(3) Å, b = 12.101(2) Å, c = 20.907(3) Å, ß = 90.875(2)°, V = 5528(2) Å(3)) were discovered. The potential porous properties of guest-containing [M(mim)] isomers were studied by thermogravimetry, X-ray powder diffraction, vacuum thermal desorption, and CO(2) sorption experiments. The isomers show distinctly different guest removal behaviors depending on their pore structures. By heating, the guest-containing isomers, 1b-1c and 2b-2d, undergo irreversible, two-step, crystal-to-crystal structural transformations to form the guest-free isomers 1a or 2a, respectively. Except 1b, other guest-containing isomers can retain their porous structures after removal of the template molecules, which were confirmed by CO(2) sorption experiments.